Splicing Advice -- Dyneema

[Dockhead]

Originally Posted by Seaworthy Lass

If you are using a ball point pen then I think you may struggle with step 1 of your method, where the standing end needs to be pushed through doubled up. You would find the 'McDonald Brummel' or simply the 'Brummel used feeding both ends' (a very simple method, just be a bit tedious if your line is very long) easier with a ball point, as only a single bit of line needs feeding through at any stage .

SWL

Actually I found it easier to push through the doubled-up line than the end, since the end would catch on the stray fibers from the standing part.

It was not hard.

[Weyalan]

Colligo Marine have excellent instructions for this
http://www.colligomarine.com/docs/mi...eb_rev_1_2.pdf

Essentially a locked Brummel splice with a tapered bury. This is my default splice for single braid Dyneema, but I have also just done a simple, long tapered bury without the lock, without ever having the splice fail (N.B. whipped and sewn through for a couple inches at the throat of the splice)

[40 South]

The locked brummel splice with 72 x diameter tapered bury is what I used for my Dynex Dux (a form of Dyneema) standing rigging.

[jaybird1111]

https://www.youtube.com/watch?v=hh9J6AezljQ

[DefinitelyMe]

I can confirm the weakening of the line at the taper from practical experience. The longer the taper the better. If we didn't taper our winch cables enough then the eventual point of failure would be right at the point where the end of the line was buried inside the cover. We went through about 10 of these cables in the 5 years i was doing that job so got a fair amount of anecdotal evidence.

[Dockhead]

OK, so I managed to get back to this and finish the first splice.

It actually doesn't look too bad. I had no difficulty opening up the standing part into a tube -- I used a rigging fid for this. But I had a lot of trouble getting the tail into the tube. When I cut the strands to taper the tail, they fell apart into an amorphous fuzz which was hard to stuff in. I wonder what I did wrong there?

Now I guess I should whip and sew the joint with shipping twine? This step is not included in the guides I read.

[Seaworthy Lass]

Originally Posted by Dockhead

OK, so I managed to get back to this and finish the first splice.

It actually doesn't look too bad. I had no difficulty opening up the standing part into a tube -- I used a rigging fid for this. But I had a lot of trouble getting the tail into the tube. When I cut the strands to taper the tail, they fell apart into an amorphous fuzz which was hard to stuff in. I wonder what I did wrong there?

Now I guess I should whip and sew the joint with shipping twine? This step is not included in the guides I read.

It helps to tightly tape the line then cut it on the diagonal to stuff it into the fid. I use a marlin spike to help push it in.

No whipping is required for the splice you posted a link to. It is a version of a locking Brummel. The principle of the initial turns is to lock the knot and replace the need for any whipping or sewing. The strength of the knot lies not in these initial turns, but in the bury. The purpose of the initial turns is purely to secure the knot from the possibility of the tail pulling out if the line is shaken (load applied and released), so whipping is not required.

SWL
PS. I misinterpreted your initial posts. I thought you were ingeniously using a hollow biro instead of a fid and not instead of a marlin spike . My earlier comments make less sense because of this.

Taping the end also fixes the problem you had of stray bits of line snagging and making a single line difficult to push through a hole in the line.

[philtrick]

No technical input from me but there is a really good series of videos on Youtube from English Braids (Welcome to English Braids) on how to splice:

https://www.youtube.com/watch?v=4FAk...859RBRUtUFwXoA

HTH

Phil

[Dockhead]

Originally Posted by Seaworthy Lass

It helps to tightly tape the line then cut it on the diagonal to stuff it into the fid. I use a marlin spike to help push it in.

No whipping is required for the splice you posted a link to. It is a version of a locking Brummel. The principle of the initial turns is to lock the knot and replace the need for any whipping or sewing. The strength of the knot lies not in these initial turns, but in the bury. The purpose of the initial turns is purely to secure the knot from the possibility of the tail pulling out if the line is shaken (load applied and released), so whipping is not required.

SWL
PS. I misinterpreted your initial posts. I thought you were ingeniously using a hollow biro instead of a fid and not instead of a marlin spike . My earlier comments make less sense because of this.

Taping the end also fixes the problem you had of stray bits of line snagging and making a single line difficult to push through a hole in the line.

Well, for the second tail bury, I opened up the standing part with the fid, and then ran a thin, long Phillips screwdriver backwards through the hollow center. Taped the untrimmed tail to the end of it like you'd do a mouse line, and pulled it all the way through. Then trimmed and tapered it, and pulled it back inside. Much better than the first one.

The first attempt was pretty crude, and the first buried tail is too short, and the eye too small, but I'm going to use this one and try it out.

Next one will be better and prettier, I hope

[Seaworthy Lass]

Originally Posted by Dockhead

Well, for the second tail bury, I opened up the standing part with the fid, and then ran a thin, long Phillips screwdriver backwards through the hollow center. Taped the untrimmed tail to the end of it like you'd do a mouse line, and pulled it all the way through. Then trimmed and tapered it, and pulled it back inside. Much better than the first one.

The first attempt was pretty crude, and the first buried tail is too short, and the eye too small, but I'm going to use this one and try it out.

Next one will be better and prettier, I hope

Attachment 102459

Looks very good .
Do the two tapers overlap? I have never done this or seen it done, but your finished length is relatively short, so this may be needed. If they overlap then I would trim and pull through the two tapers simultaneously rather than separately so there is no risk of bunching the first taper. Does that make sense?

[conachair]

Originally Posted by Dockhead

But do I correctly understand that the splice itself is nothing else but the end stuck through the standing part twice, and then stuck up into the hollow rope to bury the end? How does that hold anything? : puzzled :

Almost but not quite, the modified brummel splice is the end through the standing part and the standing part through the end, then buried.
Though just burying the end back onto the standing part is actually a little bit stronger. Very important to taper the end. I've tested dyneema to destruction before just using lever hoists and load cells onsite, when 6mm gets above 2 tonne it really is like a bit of bar Don't taper the splice, that's where it will go.
How does it hold? Must just be friction, but it does hold. Incredible stuff.

[Cadence]

Originally Posted by Dockhead

So I've got myself some 12-strand, single-braid Dyneema, and I need to splice some pieces of it to some Barton Low Friction Rings, and to make some eye splices.

I've read various helpful things on here, and I thought this was particularly good:

www.cofc.co.nz/docs/dyneema-spectra-splicing-manual.pdf

So I think I'm just about ready to give it a try. But do I correctly understand that the splice itself is nothing else but the end stuck through the standing part twice, and then stuck up into the hollow rope to bury the end? How does that hold anything? : puzzled :

For what it is worth or not? Try it on some cheap line first.

[Paul Elliott]

Originally Posted by Dockhead

Taped the untrimmed tail to the end of it like you'd do a mouse line, and pulled it all the way through. Then trimmed and tapered it, and pulled it back inside. Much better than the first one.

Yes, that's the way to do the tail. Or, just tuck the tail into the hollow end of the fid (use some tape to secure it if you like) and push it through the center of the dyneema line. If you are doing a 70X diameter taper, then push it through 100X or more of the line before pushing it through and back out. Pull out enough tail and then do your tapering. When done tapering, pull on the standing part of the line and the tail will bury.

[transmitterdan]

Originally Posted by Cadence

For what it is worth or not? Try it on some cheap line first.

In my experience the cheap stuff is much harder to splice than the real dyneema 12 strand single braid. If you need to practice just use a short piece of the real stuff. You can de-splice it and re-splice many times without damaging the line.

[Cadence]

Originally Posted by transmitterdan

In my experience the cheap stuff is much harder to splice than the real dyneema 12 strand single braid. If you need to practice just use a short piece of the real stuff. You can de-splice it and re-splice many times without damaging the line.

You're probably right. I watched the video and that is not what I had in mind.
I was thinking of actually splicing the sheath after putting to core up the opposite sheath. I see what someone posted about a Chinese handcuff is in effect the slice. I guess you're never to old to learn.